The BVB chief criticised the timing of the Germany international's decision to swap clubs and has insisted Marco Reus is going nowhere
The talented 21-year-old agreed to swap Signal Iduna Park for the Allianz Arena for an estimated €37 million in April, just before a crucial Champions League semi-final game with Real Madrid.
The move angered many BVB fans and Zorc admits it was frustrating to find out Gotze would leave, although he has criticised the extreme reaction in some quarters.
"Of course we were disappointed about his decision to leave us - especially about the timing. One has to admit that," Zorc told Bild.
"However, the vilification of him I condemn in the strongest terms. I have recently congratulated him for his birthday [June 3]."
Zorc shot down suggestions that Gotze's fellow Germany international Marco Reus might be the next star exiting Jurgen Klopp's squad.
"We have long-term plans with Marco, which is also discussed with him that way," he added.
The 24-year-old Reus has a contract with BVB until the summer of 2017.